1. Field of the Invention
This invention relates a blood pressure measuring apparatus capable of automatically sensing inadequate pressurization.
2. Description of the Related Art
In a blood pressure measuring apparatus which operates on the basis of the Korotkoff method, determining inadequacy of pressurization in the prior art is based on whether Korotkoff sounds are detected within a prescribed period of time following the start of blood pressure measurement, i.e., following termination of the pressurizing operation. For example, see the specification of Japanese Utility Model Publication No. 57-3296.
A problem with the foregoing method of determination is that there is no assurance that the prescribed period of time is long enough to allow fail-safe detection of inadequate pressurization under all conditions. For this reason, there is always the possibility that inadequate pressurization will not be sensed in case of a low pulse rate. If it is attempted to solve this problem by making the set period of time long enough to sense inadequate pressurization without fail even for low pulse rates, then a patient with a comparatively rapid pulse must be subjected to more pressurization than necessary and will experience discomfort due to the pressure applied. Another problem involved with rapid pulses is that inadequate pressurization is sometimes sensed even if enough pressure is actually applied. As a result, the patient is subjected to unnecessary repressurization.